Key factors improving oxygen reduction reaction activity in cobalt nanoparticles modified carbon nanotubes

Gabe, Atsushi; García-Aguilar, Jaime; Berenguer-Murcia, Ángel; Morallón, Emilia; Cazorla‐Amorós, Diego

doi:10.1016/j.apcatb.2017.05.096

Cited by 65 publications

(45 citation statements)

References 42 publications

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“…developed multiwall CNTs decorated with CoO x nanoparticles and additional introduced polyvinylpyrrolidone (PVP) as the protecting agent marked CNT_Co_1 %_500. This catalyst presented the ORR activity performance with E 1/2 at 0.8 V and

j_{L}

of −5.2 mA cm −2 . The Fe 3 Mn 1 /N‐CNTs‐100 catalyst shows not the best but also high E 1/2 and

j_{L}

compared with those reported catalysts.…”

Section: Resultsmentioning

confidence: 75%

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

et al. 2018

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A set of novel catalysts FeMn/N‐CNTs that partly maintain the core‐shell structure have been prepared successfully by calcination of analogous MOF‐74, which has bimetallic species (Fe and Mn) and a cheap organic ligand (2, 5‐dihydroxylbenzoic acid, DHBA) with melamine as additional nitrogen source. These catalysts exhibit a distinctive microstructure of Fe−Mn alloys surrounded by N‐doped carbon nanotubes (CNTs). Electrochemical methods have been employed to investigate their activity in oxygen reduction reaction (ORR) in alkaline solution. The highest ORR performance of Fe3Mn1/N‐CNTs‐100 shows that the half wave potential is at 0.865 V and the kinetic current density (at 0.9 V) is 1.447 mA cm−2, which are higher than those of commercial Pt/C (0.855 V, 0.946 mA cm−2). In addition, Fe3Mn1/N‐CNTs‐100 is much more durable than commercial Pt/C under the conditions tested. The highly efficient ORR performance may be attributed to the unique microstructure and large surface area with appropriate pore size, as well as to the synergistic effects between the pyridinic N species and the Fe−Nx species that play important roles in ORR in alkaline solution. However, in acid medium, only Fe−Nx species catalyze ORR and pyridinic N species are limited to work as the active sites. This study may prompt others to explore the development of heteroatom‐doped CNTs surrounding particles as efficient catalyst for ORR and fuel cell applications.

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j_{L}

of −5.2 mA cm −2 . The Fe 3 Mn 1 /N‐CNTs‐100 catalyst shows not the best but also high E 1/2 and

j_{L}

compared with those reported catalysts.…”

Section: Resultsmentioning

confidence: 75%

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

et al. 2018

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“…Because Co ions with the same valence on the different exposed faces or different kinds of spinel oxides equip with various occupancy of 3d electron, which is a non‐negligible factor to electrocatalytic activity of OER . The Co 3 O 4 nanocrystals are also potential alternates for novel metal Pt to catalyze ORR, but the activity and stability are still inferior to commercial Pt/C in fuel cell operation . To enhance the ORR electrocatalytic performance of Co 3 O 4 , various approaches have been adopted, such as crystal‐plane‐ or morphology‐controlled, size‐controlled, electroconductivity‐enhanced and doping .…”

Section: Introductionmentioning

confidence: 99%

Crystal‐Plane‐Dependent Activity of Spinel Co₃O₄ Towards Water Splitting and the Oxygen Reduction Reaction

et al. 2018

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Insights into the relationship between the crystal planes of metal oxides and the catalytic activity of the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) are essential for developing efficient renewable energy technologies. Herein, spinel Co3O4 nanomaterials were synthesized controllably with the specified morphologies of nanocubes, nanosheets, and nanoplates with different exposed planes of {100}, {110}, and {111}, respectively. The effects of the crystal planes of Co3O4 on the activity for the OER, ORR, and HER were subsequently investigated in alkaline media. Different electrocatalytic performances are possibly attributed to the abundance ratios of Co3+/Co2+ over the different exposed planes. The surface Co3+ ions exhibit higher activity for the OER and HER, whereas the surface Co2+ ions exhibit better performance for the ORR; moreover, higher electroconductivity enhances the polarization current for ORR and HER except OER.

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“…And these numbers were calculated to be 4.0 (Pt/C), 3.9 (CoO/NC2), and 3.7 (CoO/C) at a potential range of 0.3 ‐ 0.6 V vs. RHE, respectively. According to these results, CoO/NC2 primarily undergoes a four‐electron oxygen reduction process, and its oxygen molecules can be reduced to hydroxide ions at a wide range of potential ,,…”

Section: Resultsmentioning

confidence: 99%

Enhanced Oxygen Reduction Stability and Activity by Co and N (or O) Interaction in CoO on N‐Doped Carbon Prepared through Spray Pyrolysis

2018

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Although the development of a highly active and cost‐effective electrocatalyst for the oxygen reduction reaction (ORR) is necessary, it is a challenging issue for commercially viable energy conversion applications such as fuel cells or metal‐air batteries. In this study, we synthesize nitrogen‐doped, carbon‐supported CoO catalysts (denoted as CoO/NCs) with high stability and activity. The CoO/NC is prepared by one‐pot spray pyrolysis, which is simple and has an easily scalable synthetic route. In an effort to find a better catalyst composition for ORR activity, several catalysts are synthesized by controlling the concentrations of the solutions that contain carbon, urea as the nitrogen source, and a cobalt precursor. The catalysts are then characterized using various methods to comprehensively study their properties coupled with ORR kinetics and stability. The CoO/NC2 catalyst shows higher catalytic activity towards ORR than the other in‐house prepared catalysts. It is comparable to commercial Pt/C and has very high stability for 80 h in an alkaline medium. Systematic analyses clarify that the superior electrocatalytic performance of CoO/NC2 stems mainly from its enhanced electron density and pathway by heteroatom doping and its modified carbon nature during spray pyrolysis.

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Key factors improving oxygen reduction reaction activity in cobalt nanoparticles modified carbon nanotubes

Cited by 65 publications

References 42 publications

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

Crystal‐Plane‐Dependent Activity of Spinel Co₃O₄ Towards Water Splitting and the Oxygen Reduction Reaction

Enhanced Oxygen Reduction Stability and Activity by Co and N (or O) Interaction in CoO on N‐Doped Carbon Prepared through Spray Pyrolysis

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Key factors improving oxygen reduction reaction activity in cobalt nanoparticles modified carbon nanotubes

Cited by 65 publications

References 42 publications

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

Crystal‐Plane‐Dependent Activity of Spinel Co3O4 Towards Water Splitting and the Oxygen Reduction Reaction

Enhanced Oxygen Reduction Stability and Activity by Co and N (or O) Interaction in CoO on N‐Doped Carbon Prepared through Spray Pyrolysis

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Crystal‐Plane‐Dependent Activity of Spinel Co₃O₄ Towards Water Splitting and the Oxygen Reduction Reaction